Fire alarm signal stations



Des. 6, 1955 M. LEVY FIRE ALARM SIGNAL STATIONS Original Filed May 13, 1952 o .9710 .3121 smear .Enigm- A TTOENEY United States Patent FIRE ALARM SIGNAL STATIONS Morris Levy, Philadelphia, Pa.

Original application May 13, 1952, Serial No. 287,645, now Patent No. 2,686,857, dated August 17, 1954. Digided and this application May 25, 1953, Serial No. 35 ,947

4 Claims. (Cl. 200-142) My invention relates to a new and useful fire alarm signal station and a primary object thereof is to produce a signal station including an electric switch normally retained in an open condition by a frangible panel which may be broken or ruptured automatically from the inside due to the presence of abnormal heat in the vicinity of the station or broken by the manual operation of means to strike a blow on said panel.

This application is a division from my application for patent filed May 13, 1952, Serial No. 287,640, now Pat. No. 2,686,857.

Another object of the invention is to provide a re alarm signal station including a switch normally maintained in an open position by a frangible panel which may be broken by a spring actuated hammer directly or indirectly held in a neutral or cocked position by a fusible element, said hammer being releasable manually or when the fusible element melts due to the presence of abnormal heat.

Another object of the invention is to provide a spring actuated hammer projectable in a straight line and controlled by a spring operated bar which, in turn, is maintained in a retracted position by a fusible link that when manually detached or melted by abnormal heat will liberate the bar to release the hammer for breaking the panel to allow the switch to close.

A further object of this invention is to incorporate a fusible element in the frangible panel whereby the switch may be released upon the melting of said fusible element or the breaking of the panel by a separate instrument wielded from the outside of the signal station.

A still further object of the present invention is to provide a fire alarm signal station including a switch normally maintained in an open position by a frangible and fusible panel which when broken or melted will release the switch to permit it to close.

With the above and other objects in view this invention consists of the details of construction and combination of elements hereinafter set forth and then designated by the claims.

In order that those skilled in the art to which this invention appertains may understand how to make and use the same I will describe its construction in detail referring by numerals to the accompanying drawing forming a part hereof, in which:

Fig. l is a perspective view of a fire alarm signal station embodying the features of my invention in one type of structure, a portion of the body being broken away.

Fig. 2 is a longitudinal sectional view on the line 2 2 of Fig. 1.

Fig. 3 is a fragmentary sectional view on the line 3 3 of Fig. 1 to illustrate details of construction.

Fig. 4 is a sectional view of another type of lire alarm signal station wherein a fusible element is incorporated in the frangible panel.

Fig. 5 is a similar view of a further modification utilizing a frangible and fusible panel showing it in condition to normally retain the switch in open position.

2,726,302 Patented Dec. 6 1955 Fig. 6 is a like view of the latter station upon the melting of a portion of the panel whereby the switch is closed.

In carrying out my invention as herein embodied, particular attention being had first to Figs. l, 2 and 3, 10 represents the body of the station, preferably produced from appropriate dielectric material, having a chamber 11 in which is mounted the terminal member 12 held in place by fastening devices 13, such as screws or bolts, and through one of which said terminal member is electrically connected with one side of an electric circuit including an audible or visible alarm device (not shown).

Attached to said terminal member 12 is a movable spring contact 14, the free end 15 of which underlies a stationary contact member 16 mounted in the chamber 11 and held in place by fastening devices 17, such as screws or bolts, and through one of which said stationary contact is electrically connected with the other side of the electric signal circuit.

The free end 15 of said movable spring contact 14 is reciprocatingly positioned beneath the stationary contact member 16 within a recess 18 in the bottom of the chamber 11 to accommodate the movements of the free end of said movable spring contact. Said movable contact is fashioned to provide an outwardly projecting knee 19 for a purpose to be described below.

The outer open end of the chamber 11 is covered by a frangible panel 2G, set in a rabbet 21 surrounding said open end of the chamber and held in place by fastening devices 22, such as screws. Said panelengages the knee 19 of the movable spring contact to depress and normally hold the free end of said spring contact out of engagement with its companion stationary contact member 16 whereby the switch is normally open until such time as the panel is broken.

By preference, a cavity 23 is formed in the back of the body 10, in alignment with the chamber to produce a partition 24 so that the exposed ends of the fastening devices 13 and 17 will be housed at the rear of the station and whereby other recesses or openings may be produced in the form of holes to cheapen the costs of manufacture.

A longitudinally propelled hammer 25 is supported by the partition 24 underneath of and substantially at right angles to the frangible panel 20 and is urged towards the latter by a spring 26.

The hammer is normally retained in a retracted position by a control bar 27 which, for purposes of illustration, is shown as having a longitudinal slot 28 opening into a hole 29 large enough for the passage of the hammer, particularly a portion of its head, and the spring and said hammer has a reduced neck 30 to be received in the slot 28.

The forward portion of the control bar 27 is located within the chamber 11 and extends through a channel 31 into a compartment 32 at the far end of the body and offset relative to the chamber 11. The compartment 32 opens to said far end of the station body and is normally closed by a cover plate 33. The rear end of the control bar 27 is bent at right angles to provide a lip 34 through which is threaded a screw 35 bearing against a coil spring 36 whereby the control bar is urged rearwardly. The tension of said spring is regulated by said screw 35.

The control bar 27 is moved forwardly by a pull rod 3 which, in effect, is a part of said bar although said parts may actually be separate pieces as shown. The pull rod extends through the near or forward end of the station body and is provided with any suitable type of handhold 38. This pull rod has a reduced neck 39 providing a circumferential groove to receive the fusible element 40 the latter having an open end slot 41 whereby said fusible element may be detachably mounted on the pull rod neck ICC and against the adjacent end of the station body. The neck 39 is located so that when the fusible element 40 can be placed thereon and caused to engage the end of the housing the position of the control bar will be such that the hammer neck 30 will be in the slot 28 and the springs 26 and 36 will be compressed.

In operation, when the fusible element 40 is melted by abnormal heat or said fusible element manually removed from the pull rod 37 the control bar 27 will be forced inwardly or rearwardly by its spring 36 until the hole 29 in said bar is aligned with the hammer 25 thereby releasing the latter so that it can be propelled forwardly by its spring 36. The hammer will strike the panel 19 with suhcient force to break said panel and release the spring contact 14 whereupon it will engage the stationary contact to close the switch and produce an alarm.

To reset the station, the hammer is pushed back, the control bar 21 pulled forwardly and the fusible element replaced on the pull rod, if said fusible element has been removed intact, or a new one substituted if the former one has been melted or otherwise damaged. Finally a new frangible panel 20 is substituted for the broken one and secured in place to depress the movable spring contact and thereby open the switch.

The station shown in Fig. 4 includes a body 42 having the customary switch holding chamber 43 across the open end of which is disposed the usual frangible panel 44 which, in this instance, has a fusible element 45 in the form of a plug or equivalent structure fixed in a hole 46 in said panel. Within the chamber 43 is mounted the usual switch including the terminal member 12, the stationary contact 16, the movable spring contact 14 having one end attached to the terminal member and the other or free end underlying the stationary contact and reciprocatingly received in the recess 18, said movable spring contact being provided with an outwardly projecting knee 19 coacting with the panel through the medium of the fusible element 45 which it directly engages. The fusible element 45 projects into the switch chamber 43 a suicient distance to depress the movable contact out of engagement with the stationary contact to normally maintain the switch in an open condition but when the fusible element is melted there is sufficient space provided to allow said movable contact to spring outwardly and engage the stationary contact.

In operation, any abnormal heat caused by a fire in the Vicinity of the station will melt the fusible element 45 and release the movable contact whereby the switch will be closed and an alarm sounded. To actuate the device manually the panel is broken by a hammer provided for this purupose or any convenient instrument can be used. To reset the device a new panel with the fusible element thereon is put in position to replace the damaged or destroyed one.

The modification illustrated in Figs. and 6 comprises an appropriate station body 47 having the usual switch holding chamber 48 across the open end of which is disposed a frangible and fusible panel 49. In the chamber 48 is mounted the usual switch including the terminal member 12, the stationary contact 16, the movable spring contact 14 having one end attached to the terminal member and the other or free end underlying the stationary contact and reciprocatingly received in the recess 18, said movable spring contact being provided with an outwardly projecting knee 19 coacting with the panel 49.

The movable spring contact 14 is normally depressed by the panel so that theswitch is open, as shown in Fig. 5. If the panel is broken by the use of an outside instrument or a re reaches the station to melt or soften said panel the movable spring contact will deform, rupture or push a hole 50, Fig. 6, in said panel to permit said movable contact to move outwardly a sulcient distance for it to engage the stationary contact and close the switch, as depicted in said Fig. 6, whereby an alarm will be produced.

Of course I do not wish to be limited to the exact details of construction herein shown and described as these may be varied within the scope of the appended claims without departing from the spirit of my invention.

Having described my invention what I claim as new and useful is:

1. A tire alarm signal station comprising a body with a chamber having a frangible panel disposed across the open outer end thereof and to be ruptured from the inside of the body, an electric switch located in said chamber and including a movable spring contact the depression of which opens the switch and coacting with said panel to normally be maintained in the depressed position, the rupturing of the panel releasing the movable contact member to close the switch.

2. A lire alarm signal station comprising a casing provided with a chamber having a frangible panel disposed across the open outer end, an electric switch located in said chamber and including a movable spring contact the depression of which opens the switch coacting with said panel to normally be maintained in the depressed positon, a spring actuated longitudinally projectible hammer within the chamber for breaking said panel and means including a detachable fusible element for holding said hammer retracted which when said fusible element is melted or manually detached will liberate the hammer to break the panel and release the movable contact to close the switch.

3. A re alarm signal station comprising a body having a chamber with an open front, an electric switch located in said chamber and including a movable contact con stantly urged towards said open front and having a portion projecting outside of the chamber, a frangible panel disposed across the open front of said chamber and engaging the projecting portion of the movable contact to depress the latter for opening the switch, a spring actuated hammer within the chamber for breaking the panel, a spring actuated control bar to normally retain the hammer retracted and having a hole through which a portion of said hammer is projected when the hole in the bar aligns with the hammer, a pull rod connected with said bar and protruding outside of the body and a fusible element detachably mounted on said pull rod to normally maintain said bar in a projected position under tension, the removal or melting of said fusible element releasing the hammer to break the panel and thereby release the movable Contact whereby the switch will be closed.

4. A re alarm signal station comprising a body with a chamber having a frangible panel disposed across the open outer end thereof, means located within said chamber and normally maintained in a retracted position by fusible means, the release of the first mentioned means rupturing the frangible panel from the inside of the body, and additional means within said chamber to complete an electric circuit of a fire alarm, said panel also capable of being broken by a blow of an instrument delivered to the exterior thereof.

References Cited in the file of this patent UNITED STATES PATENTS 743,600 Uytenbogaart Nov. l0, 1903 1,095,382 Clorius et al. May 5, 1914- 1,106,151 Matthews Aug. 4, 1914 2,570,823 Levy Oct. 9, 1951 

